Cement blocks are commonly used in the construction industry. Since cement is a heavy substance, it is desirable to make cement blocks lighter for ease of use and to help prevent injury to workers caused by lifting the blocks.
Various methods have been proposed in the prior art to form lightweight cement blocks utilizing sawdust as a component. The addition of sawdust, however, tends to interfere with the setting of the-cement as sawdust tends to absorb water from the mixture. The presence of sawdust weakens the bonds in the cement and frequently decreases the setting time of the blocks. Sawdust also decreases the strength of cement blocks and increases flammability.
The methods for forming lightweight cement blocks have included the addition of a number of other substances to the sawdust cement mixture--such as alum, lime, asbestos, iron rods, calciumoxychloride and sodium hydroxide. The products produced by these methods are complicated and expensive thus limiting commercial sales.